Hydraulic Clutch Slave Retrofit Kit
Hydraulic clutch release systems have gained wide acceptance in the aftermarket as a keen solution to both engine conversion and stock clutch linkage replacement scenarios.
Novak's Hydraulic Clutch Slave Retrofit has evolved into its third and best rendition, as our #HCRC. It bolts to the popular Chevrolet 90 degree style bellhousings - typically Small Block V8 & V6 and Big Block V8, I6 and Iron Duke style bellhousing flanges.
Option I - 7/8" bore
Option II - 3/4" bore (our most popular size)
Our #HCRC clutch kit has been engineered to bolt to most Chevrolet 90 degree style bellhousings and to work with their associated pressure plates.
All included components work as a system to insure a straightforward installation. The arm provides the proper ratio for the great majority of pressure plates and the T6 hardened and hard anodized billet aluminum slave cylinder and piston are absolutely durable, yet rebuildable or replaceable down the road, if necessary.
Available Kit Versions
Hydraulic clutch release systems are typically engineered to have a 1:1, master-to-slave ratio, where the leverage is not obtained through differential hydraulics. The force is obtained through the leverage provided by the clutch pedal and then the release arm / fork at the throwout bearing, like a conventional mechanical clutch - the method of transmitting the force is the only difference. These principles are discussed here.
As such, the installer will generally choose between our 3/4" bore version or our 7/8" bore version to best match the diameter of their master cylinder.
- Choosing a larger slave for a smaller master may create a situation where the pedal pressure is reduce, but the lessened travel may not fully release a clutch.
- Choosing a smaller slave for a larger master may create a situation where there is excessive pedal pressure. However, the Novak 3/4" bore slave has more travel than OEM units and typically work with 7/8" master cylinders without blowing out. This is helpful if the throwout bearing needs more travel for release, but note that this is not a substitute for not choosing the right length throwout bearing.
For your best benefit, read and understand the principles of working with hydraulic clutch release systems and determine the applicability for your vehicle.
* Note that Full Size Jeeps (Wagoneer, Cherokee, J Truck) vehicles do not accomodate conventional, firewall mounted master cylinders due to the brake booster and the electrical bulkhead connector. If converting one of these Jeeps to hydraulic clutch release, the installer will need to custom configure a master cylinder accordingly.
The Novak #HCRC has been proven to work on big clutch & small clutch as well as big bore and small bore Chevy bellhousings. We have verified that the following GM bellhousing part numbers have the necessary block / bellhousing flange style that the #HCRC utilizes for mounting:
There are surely more Chevy bellhousings not yet listed, but these are the major ones. If you are not sure of applicability, send us a digital picture or two via e-mail, and we will let you know. See our contact page.
Aftermarket bellhousings such as Lakewood, McLeod and others have thus far proven compatible with this system.
Chevrolet Cast Iron Bellhousings
The classic cast iron bellhousing as found on so many Chevrolet engines from 1955 through the early seventies can be made to be compatible with this kit with two modifications:
- The through-boss at about 9 o'clock (see highlight in image, right) must be milled down to the same height as the through-bosses at 10 o'clock and 11 o'clock. This is a simple machining procedure and we would expect most machine shops to be able to bill it out at around 20 minutes.
Alternatively, one could install a spacer on the boss at 11 c’clock and adjust the pushrod shorter, accordingly. This cylindrical thru-spacer can measure 0.385” - 0.410” ID x 7/8” OD x 0.925” tall.
Once completed, our mounting bracket will sit at the same level as it does on the later aluminum bellhousings.
- The clutch fork window is too narrow for the provided, hydraulic style release arm. Widening this window will be required.
|Big Block Installations
Installers with Chevy Big Blocks should be aware that the line fitting is very close to the oil filter boss and may require grinding.
Clearance for the standard diameter oil filters is sufficient without modifications.
- Buick, Olds, Pontiac or Cadillac style bellhousings
- The Iron Duke bellhousing as made by Jeep for the 1980 - 1981 CJ's
- The Advance Adapter's conversion Chevy bellhousing is not compatible without clearancing two aluminum recesses in the bellhousing-to-block bolt areas
- GM bellhousing #3849309
Hydraulic Lines & Fittings
Optional Hydraulic Line Adapters for Jeeps
These useful adapter fittings (left) permit the adaptation of our #HCRC to 1991-present Jeep master cylinders that use the o-ring style fittings.
These fittings each feature a male 1/4" DOT threaded ends so that the installer can use or make standard hydraulic lines or hoses for the particular situation. The tip inserts into your 1991-1995 Jeep YJ (and 1991-1996 Jeep XJ) or 1997-present Jeep TJ & XJ master cylinder using the factory style o-ring and retaining pin. We recommend that you verify your particular fitting with the image and descriptions below prior to ordering.
Note that 1980-1986 CJ's and 1987-1990 YJ's master & slave cylinders already feature a female DOT fitting and do not require these adapter fittings.
A common example of hydraulic hose / line use of these adapters when installing the #HCRC kit is to buy or fabricate a line with a female DOT 1/4 fitting for the adapter/master side of the circuit. This line should then feature a male DOT 1/4 end for the slave side of the #HCRC cylinder port.
Optional Rebuild Kits